# subnet mask(서브넷 마스크) 비트 별 정리 #
bit netmask Cisco mask hosts usable hosts Class /4 240.0.0.0 15.255.255.255 268435456 268435454 /5 248.0.0.0 7.255.255.255 134217728 134217726 /6 252.0.0.0 3.255.255.255 67108864 67108862 /7 254.0.0.0 1.255.255.255 33554432 33554430 /8 255.0.0.0 0.255.255.255 16777216 16777214 A Class /9 255.128.0.0 0.127.255.255 8388608 8388606 /10 255.192.0.0 0.63.255.255 4194304 4194302 /11 255.224.0.0 0.31.255.255 2097152 … Read more